My next holiday

I would like to travel to London next summer to speak to english. ("... to practice English" sounds better)

I visited London six years ago. I received a scholarship to study english for three weeks. I lived with a english family who had a very big house very big. The house had a huge garden, six bedrooms, two bathrooms (bathroom needs plural 's' since it's more than one), a terrace in on the last floor. I used to attend to class every day, there I met many people of different country  countries We spoke a lot, so we improved (needs to be past tense) to the english language   our English OR are you trying to say "to improve our English"?? 

Nowadays, my dream is to travel to London << for know of my english family >>???? "to see/visit my English family"?  and remember the days those  that which were incredible!

My next holidays

I would like to travel to London next summer to speak to English.

I visited London six years ago. I received a scholarship to study English for three weeks. I lived with an English family who had a very big house very big. The house had a huge garden, six bedrooms, two bathroom, and a terrace in the last top floor. I used to attend to class every day. there I met many people from different countries. We spoke a lot, so we improved our English.

Nowadays (this word is used correct but a bit literary, in more informal writing most people would simply say "now") my dream is to travel to London, visit of my English family, and remember those incredible days those which were incredible!

My next holidays

I would like to travel to London next summer to speak to english English. 

I visited London six years ago. I received a scholarship to study  english English for three weeks. I lived with an english English family who had a house very big house. The house had a huge garden, six bedrooms, two bathrooms, and a terrace in on the last floor. I used to attend to class every day, there where I met many people of from different country  countries. We spoke a lot, so we improved to the our ability to speak the english English language.

Nowadays, my dream is to travel to London for know of to learn about my english English family and remember the days those which were incredible days.